White-Light Emission from a Host–Guest Composite between Carboxylatopillar[5]arene-Modified N‑Doped Carbon Dots and Rhodamine 6G for Rutin Detection

The construction of tunable white-light-emitting materials has garnered increasing attention in the scientific community. In this study, N-doped carbon dots (N-CDs) were surface-modified with carboxylatopillar[5]arene (CP[5]) using an EDC–NHS coupling reaction to create CCDs. CCDs were then conjugated with rhodamine 6G (R6G) through host–guest interactions to fabricate the CCDs–R6G composites. These composites produced two-color fluorescence emission peaks at 447 and 557 nm when excited by a wavelength of 340 nm. Excitingly, white-light emission (0.28, 0.30) can be readily achieved by varying the R6G concentration. To further explore potential applications, a new detection method for rutin (RT) based on the inner filter effect (IFE) was developed. Experimental results verify the practicality and reliability of the fluorescence sensor based on CCDs–R6G composites for RT detection in real samples.